Typewriting machine



Oct. 21 1924, 1,512,600

E. B. HESS ET AL TYPEWRITING MACHINE Filed Nov. 12, 1923 2 Sheets-Sheet 1 Oct. 21 I924. 1,512,600

E. B. HESS ET AL TYPEWR ITING MACHINE Filed m'sv. 12. 1923 2 Shoots-Sheet 2 Patented Oct. 21, 1924.

UNITED -STATE S,

1,512,600 PATENT OFFICE.

EDWARD HESS, OF NEW YORK, AND LEWIS G. MYERS, OF FREEPORT, NEW YORK, ASSIGNORS T0 ROYAL TYPEWRITEB COMPANY, INCL, OF NEW YORK, N. Y., A COR ronA'rIoN on NEW YORK.

TYPEWBJITING MACHINE.

Application filed November 12, 1923. Serial No. 674,245.

To all whom it may concern:

Be it known that we, EDWARD B. Hnss and Lnwrs G, Mrnns, citizens of the United States, and residents, respectively, of New York, in the county of New York and State of New York, and Freeport, in the county of Nassau and State of New York, have invented certain new and useful Improvements in Typewriting Machines, of which the following is a specification.

This invention relates to the escapement mechanism oftypewriting machines, and the object of the invention is to provide an escape'nient involving the use of a limber or stepping dog and a rigid or'non-limber dog co-operating with a toothed escapement wheel or rack in suchmanner as to reduce friction to a minimum and provide increased speed of operation.

The limber dog employed is preferably of the round nose type as illustrated in Royal machine Patent No. 1,094,162, in which the end of the working face which contacts with the wheel teeth is rounded so that there is substantially line contact betweenthe two engaging parts. The rigid dog employed is a roller dog, as illustrated in Royal machine Patent No. 827,976, in which the thrust is taken up by the pintle ofthe roller and the'only friction present occurs in the turning of the roller on its pintle, and there is substantially a line contact between the roller and the cooperating faci of the teeth of the escapement wheel or rac Such dogs have been before used in Royal machines but only in connection with an escapement wheel with teeth having their faces at right angles to the direction of movement thereof' According to this invention the faces of the teeth of the escape ment wheel are so formed as to so cooperate with the kinds of dogs mentioned to produce a more rapid action and one in which there is much less friction or wear on the operating'parts than in previous escapements.

we provide a right angle portion on the working face of each tooth of the escapement wheel which is very small'but is sufficient'to hold thepartsin normal position. The engaging portions of'this right angle face and the round nose stepping pawl which is normally in contact therewith are very small and but little friction occurs in the disengagement of the pawl from the wheel to permit the stepping movement of the carriage.

Each wheel tooth has an obtuseangle portion on its working face extending from the right angle portion and is of considerably greater extent which portion cooperates with the roller dog, and as the roller dog moves out of engagementwith the wheel tooth, the limber dog moves back into position to be engagedby the subsequent tooth of the wheel in the usual manner.

The non-working faces of the teeth and the non-working face of the round nose dog are relieved in the usual manner to facilitate re-engagement of the parts without any interference in rapid operation.

In the drawings Figure I is a rear view of the new escapement mechanism in operative position with apart of the machine frame in outline and section.

Figure 2'is a view on an enlarged scale of a part of the escapement wheel and the upper ends of the two cooperating dogs.

Figure 3 is a section on the line 33 of Figure 2 showing in plan the shape of the working face of a wheel tooth and the manner in which the roller dog cooperates therewith.

' Figure 4 is a horizontal section through the escapement tooth and the pintle of the roller dog, showing the roller in elevation,

Figure 5 is a side elevation of the roller and wheel tooth.

Figure 6 is an inverse view of Figure 5.

In Figures 4, 5, and 6, there is a graphical illustration of the various angles and the action of wheel stress in a direct line toward the pivotal center of the roll.

The escapement frame B is mounted on the machine frame in any suitable way. This frame 13 carries a shaft on which are mounted the escapement wheel C and a pinion D which meshes with the usual rack E carried by the carriage. Mounted on pintles b in the escapement frame B is a dog rocker F which carries a limber dog H pivotally mounted at h and normally in engagement with 'a tooth of the escapement wheel C but stepped by a spring h when disengaged fromsaid escapement wheel. The dog rocker also carriers a rigid dog K which coopcrates with the teeth of the escapenient wheel G, alternately with'the dog H. The dog rocker may be moved in one direction by any well known or desired means and it may be returned to normal position by the usual spring fastened at one end to the dog rocker F and at the other end to the escapement frame B.

Mounted on a vertical pintle 7c in the upper end of the rigid dog is a roller K which contacts with the teeth of the escapement wheel C. This roller may be cylindrical or may have a substantially spherical outer surface as illustrated, in which case it has practically point contact with the working face of the escapement teeth. Because of this fact and because all thrust is taken up by the pintle of the roller, there is practically no friction to be overcome, and there is none between the face of the roller and the face of 'the tooth.

' The working face of each escapement tooth has a portion M which is disposed at I vary, but excellent results right angles to the direction of movement of the tooth. This face is very short, pref erably between one and two one-hundredths of an inch, and it cooperates with the rounded end H of the stepping or limber dog H. The remainder of the working face of each tooth of the wheel C is formed at an angle to the direction of movement of the wheel as indicated at N. The angle may have been obtained when it is about 12. This angled face N cooperates with the roller K,'and since the escapement wheel is impelled in the direction of the arrows in Figures 2 and 3, this movement will bring the limber (log back into position to be engaged by the next subsequent tooth of the wheel. Due to the type of dog employed in which the friction is all taken by the pintle on which the roller is mounted and to the fact that there is practically only a line or point engagement between the roller and the angled face of the escapement teeth, a very eflicient and rapid result is obtained.

The right angle-portion M which normally'engages the limber dog, rests against the rounded end H thereof with substantially a line contact. Although there is very little friction between the two parts and the dog is readily disengaged by the operation of the dog rocker, nevertheless the tooth bears against the dog with a direct ressure and there is no tendency for accidental disengagement.

Where the roller employed has its outer surface spherical, there is theoretically only a point contact between the surface thereof; and the tooth of the wheel, and this will result in a very rapid operation of the es capement. The escapement thus differs widely from previous types employing beveled faces on the escapement wheel teeth, but in which the engaging faces of the dogs were parallel to the faces of the teeth so that there is a surface engagement which is neces sarily productive of much friction.

To permit of adjustment to afford freedom of operation within working limits, it is customary in the assembling of escapement mechanisms that the rocker plate be mounted upon adjustable pivots for lateral adjustment.

In this connection this invention discloses material advantages between the engaging parts, as each escapement wheel tooth has a radial portion and also an angular portion which latter cooperate with the roller dog when the escapement rocker plate is adjusted laterally.

It is to be noted that the angle of the radial portion of the tooth is changed. with respect to its point of engagement with the periphery of the roll, thereby increasing the sine of the angle of contact with the roller dog, and at such time the radial portion is tangentially in contact with the vertical periphery of the roller and also at such time the angular portion is tangentially in engagement with the horizontal periphery of the roller. This arrangement therefore affords a self-aligning condition between the working elements which constitute an escapement of the type illustrated.

It is obvious that both the right angle portion M or the angled portion N of the escapement tooth are radial portions. In the event of transverse adjustment of the dog rocker, the angled portion N will vary its point of engagement with the roller dog as indicated in Figures 5 and 6. Obviously the engagement will always be a tangential one and always at the same distance from the center of the roller dog, although the engaging portion of the tooth will be at different distances from the center of the es capement wheel. The operative engaging relation is always a tangential relation and the operation will not be effected by the transverse adjustment.

The invention has been illustrated as embodied in an escapement employing a toothed wheel, but the details may be somewhat varied, and it is to be understood that the invention is limited only by the scope of the appended claims.

We claim as our invention:

1. An escapement mechanism comprising a dog rocker, a round nosed limber dog and a rigid roller dog carried thereby, and an escapement rack cooperating therewith, each tooth of the escapement rack having a working face comprising a right angle portion cooperating with the round nosed dog and an angled portion cooperating with the roller of the rigid dog.

2; An escapement mechanism comprising a dog rocker. a limber dog and a rigid roller dog carried thereby, and an escapement rack a! e um. m... -iMaM-mwith which said dogs cooperate, each tooth of said rack having a working face comprising a right angle portion having substantially line contact with the lilnber dog and an angled portion having contact with the high point of the roller of the rigid dog.

3. An escapeinent mechanism comprising a dog rocker, a round nosed limber dog and a rigid roller dog carried thereby, and an escapeinent rack with which said dogs cooperate, each tooth of said rack having a working face comprising a narrow portion having substantially line contact with the round nose of the limber dog, and a much 1 larger angled portion having contact with the high point of the roller of the rigid dog.

4. An escapernent mechanism comprising a laterally adjustable dog rocker, a limber dog and a rigid dog having a curved contact face carried thereby, and an escapement rack cooperating therewith, each tooth of the escapeinent rack having a working face comprising a right angle portion cooperating with the lilnber dog and an angled portion cooperating with the contact face of the rigid dog and bearing the same operative engaging relation thereto at all adjusted positions of the dog rocker.

In testimony whereof we have hereunto subscribed our names.

EDWARD B. HESS. LEWIS C. MYERS. 

